What is the main action a writer takes when proofreading?

A. Finding a main idea

B. Choosing the best research sources

C. Gathering supporting details

D. Fixing errors

The correct answer is D - the main action a writer takes when proofreading is fixing errors. This a moment during the writing process when an author reads the writing again and tries to find grammatical and spelling mistakes that may have snuck their way into the text. It is very important to fix those mistakes before handing it over to a publisher, because nobody wants an unfinished text.